In separate sections covers general procedures for determining grain size in metals and alloys by estimation of grain size using the comparison method and by calculation of grain size number using the intercept and planimetric methods, specific procedures for austenitic grain size in steels by a range of micrographic methods, and specific procedures for metals and alloys consisting principally of a single phase. Appendices provide explanatory notes on specifying austenitic grain size limits for steel, list etching reagents, and show the standard grain size charts for untwinned grains (flat etch), twinned grain (flat etch), and heavily twinned grains (contrast etch).RECONFIRMATION NOTICEMajor stakeholders of this publication have reviewed the content of this publication and in accordance with Standards Australia procedures for reconfirmation, it has been determined that the publication is still valid and does not require change.Certain documents referenced in the publication may have been amended since the original date of publication. Users are advised to ensure that they are using the latest versions of such documents as appropriate, unless advised otherwise in this Reconfirmation Notice.Approved for reconfirmation in accordance with Standards Australia procedures for reconfirmation on 29 August 2018.